This application is directed to an assembled gas riser that conducts pressurized fluid, such as natural gas from a main to a meter, and a method of forming the gas riser. More particularly, the invention relates to a gas riser that can be formed in the field and eliminates the need for a separate interconnection with a service line extending from the gas main.
Commonly assigned U.S. Pat. No. 5,326,137 discloses a gas riser and a method of forming the riser. That gas riser, however, is a pre-manufactured assembly, i.e. manufactured in the shop and then shipped to the field as an assembled unit. The pre-assembled gas riser provides a transition connection between an underground service line, typically a plastic conduit or gas line, that leads from a main. The double-walled gas riser provides a rigid, metal conduit that houses an extension of the service line as it extends above ground for connection with a meter, valve, or meter set.
More particularly, conventional gas risers include an outer metal casing or pipe at one end and a plastic pipe or tube that extends through the outer casing and extends outwardly from one end of the outer casing. The other end of the metal pipe is connected to a delivery member, such as a gas meter manifold, at a location above ground. The plastic tube is buried underground and connected to the service line with a coupling or connector. Examples of commercially successful couplings used to interconnect the service line and gas riser are described in commonly assigned U.S. Pat. Nos. 4,229,025; 4,407,526; and 4,712,813 and form no part of the subject invention so that further discussion herein is deemed unnecessary.
It has been proposed to provide a gas riser that may be assembled in the field to eliminate a heretofore common connection between the service line extending from the gas main and connecting to the pre-manufactured gas riser, i.e. the coupling described in the above-mentioned patents. It is still necessary to address the same concerns associated with a pre-manufactured gas riser, as well as taking into consideration a secure, sealed, and easy to assemble gas riser.
The subject invention is deemed to meet these needs and others in a simple, efficient, and economical manner.